Transition from amphibians to amniotes (Talk.Origins)
- Proterogyrinus or another early anthracosaur (late Mississippian) -- Classic labyrinthodont-amphibian skull and teeth, but with reptilian vertebrae, pelvis, humerus, and digits. Still has fish skull hinge. Amphibian ankle. 5-toed hand and a 2-3-4-5-3 (almost reptilian) phalangeal count.
Note there is no indication of ancestry, and the above quote indicates some doubt that this is an ancestor to succeeding types. Furthermore there is no indication of any development of vertebrae, pelvis, humerus, and digits from more amphibian like. They are just there.
- Limnoscelis, Tseajaia (late Carboniferous) -- Amphibians apparently derived from the early anthracosaurs, but with additional reptilian features: structure of braincase, reptilian jaw muscle, expanded neural arches.
Talk.Origins is pulling an interesting trick here they are confusing any sense of relative time by going from an Epoch (Mississippian) of the geologic column to a Period (Carboniferous). The Mississippian is an epoch within the Carboniferous period, so late Mississippian would be mid Carboniferous. This would place these late Carboniferous fossils as mid-late Pennsylvanian. This designation is important to understanding the relative time under the Evolutionary time scales.
When Limnoscelis are compared to proterogyrinus, there are few real similarities. The clearest differences are posture, size of mouth, size of front limbs as compared to rear, and length of tail. No independent information is available on Tseajaia. Once again there is no evidence of any developments in the new features, they are simply there.
- Solenodonsaurus (mid-Pennsylvanian) -- An incomplete fossil, apparently between the anthracosaurs and the cotylosaurs. Loss of palatal fangs, loss of lateral line on head, etc. Still just a single sacral vertebra, though.
This is an interesting case of evolutionary double speak since "mid-Pennsylvanian" is part of the "late Carboniferous" so Solenodonsaurus would be roughly contemporaneous with Limnoscelis and Tseajaia based on uniformitarian dating methods.
While the above site contains an actual fossil, it is incomplete, with the rear missing. This makes an accurate comparison difficult, but based on what is available there is no evidence of a general trend. When you add in the fact that they would be contemporaneous based on uniformitarian dating methods, it makes Solenodonsaurus a poor example of a transitional form.
- Hylonomus, Paleothyris (early Pennsylvanian) -- These are protorothyrids, very early cotylosaurs (primitive reptiles). They were quite little, lizard-sized animals with amphibian-like skulls (amphibian pineal opening, dermal bone, etc.), shoulder, pelvis, & limbs, and intermediate teeth and vertebrae. Rest of skeleton reptilian, with reptilian jaw muscle, no palatal fangs, and spool-shaped vertebral centra. Probably no eardrum yet. Many of these new "reptilian" features are also seen in little amphibians (which also sometimes have direct-developing eggs laid on land), so perhaps these features just came along with the small body size of the first reptiles.
Because of the incompleteness of Solenodonsaurus a comparison is difficult. Solenodonsaurus is classified as "mid-Pennsylvanian" while Hylonomus is placed in the "early Pennsylvanian" so Hylonomus is dated as older than Solenodonsaurus. Once again their dating methods are ignored to form these so-called transitions.
Hylonomus and Paleothyris seem to be the same kind. There is no real evidence of a connection with other kinds. Once again the new features appear suddenly. It is also important to note that they are dated as older than Solenodonsaurus so that there is no link with "earlier" types.
This series consists of several kinds with no real evidence of any relationship. Evolutionists are also ignoring their own dating schemes in setting up this so-called transition.